(136f) Study On An Environmentally Benign Process of Ethylene Glycol Production From Syngas

Ethylene glycol is very important precursor in the plastics industry to polyester fibers and resins like polyethylene terephthalate. Currently, it is produced from ethylene, via the intermediate ethylene oxide from petroleum resources. It is necessary to search for other routes of raw materials for ethyl glycol production. A new approach to produce ethylene glycol from syngas was proposed by Ube Industries Inc. of Japan, which contains the reaction of CO coupling to form dialkyl oxalate and further hydrogenated to ethylene glycol. A pilot-plant experiment with scale of 6000t/a dibutyl oxalate synthesis in liquid-phase was finished by Ube. Compared with traditional production method, this is an environmentally benign process in that it is rather economical, a wider source of raw materials and less pollution. From later 1980s, the process of ethylene glycol production from syngas has been investigated in our lab and a pilot plant experiment of the diethyl oxalate production with scale of 300t(DEO)/a was operated steadily in a 3-month-long run. It integrated CO gaseous coupling reaction to DEO and ethyl nitrite regeneration reaction well with little exhaustion. The results showed that the total conversion of CO was 100% and the one-way conversion was 31%, the selectivity of DEO was over 95%, the catalytic space time yield ( STY ) was more than 500g?L-1?h-1. For the hydrogenation of oxalate to ethylene glycol, 2000 hrs continuous test has proved that the catalyst we prepared has good stability. The pilot-plant reaction test is still in process.